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| Vol. 18, No. 2 | Sept. 10, 1998 |
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| Vol. 18, No. 2 | Sept. 10, 1998 |
They may correctly select a red crayon and a green one, but their drawings will not even remotely resemble the original two-tone circle.
A recent report on 60 Minutes described a similar grown-up who can sing nearly 2,000 songs memorized in more than 20 foreign languages, yet is unable to do simple math.
Such are the mystifying intellectual discrepancies of those diagnosed with Williams Syndrome, a rare genetic disorder.
First recognized as a separate syndrome in 1961, it has only been in the last 30 years that persons with Williams have been recognized as a group with a unique cognitive profile.
In particular, individuals with Williams Syndrome have very large discrepancies across their cognitive abilities. One striking discrepancy is that between language and spatial skills. Their language is in many ways quite normal, but they show profound deficiencies in certain spatial skills. Because of this discrepancy between language and space, they are a perfect population for a study by Barbara Landau, professor of psychology and director of cognitive science, whose specialty is spatial cognition.
Landau, her colleague James Hoffman, psychology, and her team of graduate and undergraduate researchers recently received a $59,208 grant from the National Office of the March of Dimes for a study, entitled "Spatial Language and Spatial Congnition in Williams Syndrome." Further funding from the National Institutes of Health and the National Science Foundation is pending.
"We look at space and language and see what goes wrong," Landau explained. "We're looking at the relationship between the children's spatial abilities and language learning-how they talk about space.
"It's quite possible that you could carry on a conversation with a child with Williams Syndrome and not realize that anything is wrong. When they are just chatting, their normal interactions using language are very good. They are so personable, sweet and friendly-and so competent in many ways-that it often covers up the fact that they have a very uneven profile of cognitive abilities."
It's when tasks involving spatial relationships come into play that the limitations of Williams Syndrome become evident.
"When we ask the children to describe direction and motion, they have problems," Landau said. "For example, if a normal child watches a doll jump into a bowl (an animated video event), they might say, 'The doll jumped into the bowl.' But, when a Williams Syndrome child views the same event, they do not describe the event using the same complex verbs and prepositions.
"Instead, they might say, 'The doll went down.' This simplification may be due to faulty spatial perception (that is, they might not have perceived the event in the same way as the normal child) or it might be faulty language (that is, they might have difficulty learning rich spatial language.) Most likely it is some combination of the two. It might be hard to learn to talk about space if you have difficulty conceptualizing it."
Similarly, those with Williams Syndrome are at a loss as to how to describe the location of a dot relative to a square. Explaining that the dot is above or below the square is not something they find easy, and they often make errors, unlike normally developing children.
And, while moving a mouse on a computer seems easy for children with Williams Syndrome, when they try to replicate block patterns on a computer screen they fail.
"This is very interesting as it suggests that certain spatial skills (e.g. coordinating a mouse and a computer image) are intact, but that other skills (e.g. copying a pattern) are profoundly impaired," Laudau said.
"The children are very persistent and can tell you what they've done is not right, but they don't know exactly what's wrong," she added.
Another interesting contrast can be found by examining how the children search space for hidden objects. Although they are impaired when asked to copy patterns, they do not seem to become disoriented in space. When asked to find a coin hidden under one of several cups on a table, the children do so quite easily-even if they have moved from one place to another between the hiding event and the finding event.
The two activities "suggest real differences in the kinds of intellectual abilities that are compromised and the kinds that are spared," Landau said. "Obviously, not every spatial capacity shows a deficit.
"This is not just retardation, this is something unusual," Landau asserted.
Landau and her research team have used some of the March of Dimes funding to purchase a special eye-tracker that records the children's eye movements as they perform spatial tasks. The tiny camera is hidden in a cap that the children wear, and this allows them to freely move their head, body and eyes. The purchase of this special piece of equipment also was supported by matching funds from UD.
The children in the study will wear the cap when trying to replicate the block patterns on the computer. Tracking their eye movements may yield some clue as to what is happening in their brains as they try and fail the simple exercises.
By understanding the nature of the spatial deficits, the researchers hope to understand what parts of language go uncompromised in Williams Syndrome. Such research could lead to a better understanding of how to educate people who have the syndrome.
Forty-five families who have children with Williams Syndrome, ages 7-14, responded to a letter Landau sent asking for volunteers. Names were provided by the Williams Syndrome Association in Connecticut.
Landau says the work is still in the preliminary stages, and will likely continue over a period of years.
"Understanding the details of the cognitive profile in this syndrome will likely be extremely complex. But, ultimately, it will shed light on how brain and cognitive development become compromised by small genetic defects," she said. "This, in turn, will enhance our understanding of how normal development occurs."
-Beth Thomas
Photo by Jack Buxbaum
